It’s Kathleen Sebelius on the phone, making another important announcement about how health care reform is making a difference in the lives of ordinary citizens. But it’s very little, very late.

Because of the health care law, the health and human services secretary said via two consecutive conference calls with the press, 3.1 million young adults now have health insurance they would not have had without it. As a result, the proportion of insured adults, ages 19 to 25, has increased to nearly 75 percent. That’s because the law requires insurers to allow young adults to remain on their parents’ family plans until they turn 26, even if they move away from home or graduate from school.

Also because of the health care law, more than 200 community health centers across the country, which provide front-line medical care, are receiving $128 million in grant money, and more than 5,000 new jobs will be created as a result.

The Supreme Court decision on the constitutionality of the historic Affordable Care Act is expected early next week. So now, a few days before that announcement is due, Obama officials are trying to sell the positive parts of the law. Good luck to them. Much of the public already thinks of health care reform as the end of America as they know it, because that’s the way opponents relentlessly portrayed it.

The failure to present health care reform as the big deal that Vice President Joe Biden said it was cries out for further explication. Instead of mounting a Koch Brothers-like effort to promote its benefits, the president let the other side demonize it. Once Ted Kennedy’s booming voice was silenced, no progressive in Washington — and certainly, no one in the White House — stepped up to frame access to decent, quality health care the way Kennedy framed it — as a fundamental American right, not a privilege.

The window of opportunity for a grand, Kennedy-type argument slammed shut a long time ago. Now, braced for a drubbing by the Supreme Court, the administration is trying to do what it should have at least tried to do months ago. That would be to present the most popular aspects of health care reform in bite-size, easy to digest pieces.

Sebelius ducked away from the phone calls before the Q&A. Asked about the administration’s contingency plans in anticipation of the Supreme Court decision, Richard Kronick, deputy assistant secretary for health policy, said on Tuesday that he was not going to “go into what we may or may not do. We believe the Affordable Care Act is constitutional.” He also said the administration expects the court to affirm the law.

Yet this week’s health care message from the Obama administration felt more like a set-up for confronting an unfavorable decision. If that’s what happens, at least it presents the administration with one more opportunity to make the case it failed so miserably to make.

If the law is struck down, it could focus people’s attention on what’s at stake, such as covering children until they turn 26. Until now, no one in the White House even tried to explain the stakes to them. If the law is struck down, it might be possible to make Americans take stock of what they had with the law and what benefits they will give up.

An unfavorable decision is also an opportunity to remind Americans of the power of the Supreme Court, and the stakes when it comes to nominating future justices. This court said corporations have the same First Amendment rights as people. What if this court also rules that a $2 trillion health care market that operates in all 50 states isn’t interstate commerce? Or that an individual mandate once promoted by small-government conservatives at the Heritage Foundation is an unconstitutional overreach?

To get this message across will take more than a few half-hearted conference calls with a media now fixated on the horse race between Barack Obama and Mitt Romney. It will take believers who are unafraid to present health care reform the way Kennedy did, as the cause of his life.

Correction: In my last column, I wrote that the director of the John F. Kennedy Presidential Library and Museum does not have access to classified files in the Robert F. Kennedy Collection. The director does have access. Researchers and the general public do not.

Joan Vennochi can be reached at vennochi@globe.com. Follow her on Twitter @Joan_Vennochi.